Printable Version | Subscribe | Add to Favourites
New Topic New Reply
Author: Subject: Please can somebody help me spec coilovers?
Freestyle_998

posted on 7/3/18 at 02:16 PM Reply With Quote
Please can somebody help me spec coilovers?

Hi everyone.... this is going to be outlandishly simple to somebody.... but I need some assistance


I want to ditch the cack handed, badly "gas free" welded, bent, twangy and crooked damper/spring arrangement I currently have, for an all in one coil over unit.

This poises several questions for me....

I have this:


I feel loosing the lever system is probably the way forward, but, I don't really (at this stage) want to make custom wishbones as it just invites error and probably hassle later on.

Which brings me here: one of the lads on (thanks riggsy) here posted this up which seems more sensible.


I can probably fit in 250-300mm of unit.

I could really do with a strut to mock up my new frame - how do I guesstimate a spring rating of a 1/2 built chassis and 45 degree angle?

Second....
at the back I want to do the same - I had a mini rubber cone and damper - where i will replace the damper with another top arm mounted coilover unit.




I need to fab a top bracket for the unit. Do I get as long unit as possible? Do I get the same length as the front?

I could just get mini coilovers off the shelf, but the front ones of these will too stong spring for what i need.

Any thoughts / criticism / ideas?

Thanks!

View User's Profile View All Posts By User U2U Member
Freestyle_998

posted on 7/3/18 at 02:29 PM Reply With Quote
Looking at these babies here:

https://www.larkspeed.com/category/view/GAZUNIVSTD

Choices:
length - ie 10" Open, 7.5" Closed
1.75 or 2.0" diameter?
12 or 14mm rod?
Bush or spherical bearing?
loop - loop, or loop - pin fittings?
then spring rate!

uuugh

[Edited on 7/3/18 by Freestyle_998]

View User's Profile View All Posts By User U2U Member
obfripper

posted on 7/3/18 at 03:18 PM Reply With Quote
Have a look at the setup on the front of a quantum extreme, it's quite similar to yours but using proper coilovers.

https://xtreme.h4-turbo.co.uk/week_4.htm

You could use your exsisting shock pickup points with a bit of modification, and with the spring removed will be able to work out bump/droop positions and therefore max/min coilover length (allowing for some bump stop compression).
At a guess, i'd say your front springs will want to be in the 80-120lb/in range, if the springs you have are 2 1/4" id , use them as a starting point.
The existing spring seat can be cut off, and you'd need to cut out the centre of the outer shock mounts, then weld in sleeves either side to bolt the coilover eye bolts though.

Dave

View User's Profile View All Posts By User U2U Member
Freestyle_998

posted on 8/3/18 at 08:28 AM Reply With Quote
That s really nice build you linked up there.

Why is it better to have the shocks working on a pivot like that and not more "direct" like jamriggs?

Or does it not matter? I guess i could get a longer unit in using the pivot method....


Are you saying that I need to account for the full travel of my suspension arms to determine the open / close length? I guess that makes sense!


I need to find a nice article with suspension design in it, this is all new to me

[Edited on 8/3/18 by Freestyle_998]

View User's Profile View All Posts By User U2U Member
Schrodinger

posted on 8/3/18 at 03:40 PM Reply With Quote
One thing you need to be aware of is the effect of the angle of the force on the spring.
Your current setup has the force acting almost along the length of the spring and as the spring compresses it gets nearer to acting along the length.
on your other example the force is at something like 45 degrees to the spring and as the spring compresses the angle reduces.
Your car has at present an increasing rate effective spring and the other a reducing rate effective spring.





Keith
Aviemore

View User's Profile E-Mail User View All Posts By User U2U Member

New Topic New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.